Printer pick system

ABSTRACT

A pick system for a printer is disclosed. The pick system has at least two sets of replacement parts. Each set of replacements parts is tuned for a different type of media.

BACKGROUND

Printers use a variety of media types, for example plain paper, photopaper, transparencies, card stock and the like. The different mediatypes vary in the surface finish of the media, thickness or weight ofthe media, stiffness of the media, material of the media and the like.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic of an example pick system 100 for a printer.

FIG. 2 is a sectional side view of an example pick roller 108.

FIG. 3 is an example block diagram of a printer.

FIG. 4 is an example block diagram of the processor 302 coupled tomemory 304.

DETAILED DESCRIPTION

There are many types of printers, for example LaserJet printers andinkjet printers. Most home or office printers, regardless of the type,feed sheets of media from an input tray through a paper path, past aprint zone, and into an output tray. At the beginning of the paper path,a pick system is used to separate the top sheet from the stack of sheetslocated in the input tray. Once the top sheet has been separated, it isfed through the paper path, past the print zone, and into the outputtray.

The pick system typically comprises a pick roller, a separation pad orseparation roller, some type of spring tensioning system and may containa motor lift mechanism. The pick system is typically optimized for themedia type most commonly used in the home or office environment. Themost commonly used media in the home and office is plain paper.Therefore the pick system is typically optimized for plain paper. Whenoptimizing a pick system, the weight or thickness of the media, thesurface finish of the media, the stiffness of the media and the materialof the media are considered.

When other types of media that have different characteristics are loadedinto the input tray, the pick system may not perform as well. Forexample, when very thin or light weight media is used, the pick systemmay have more frequent multi-pick events. A multi-pick event is whenmore than one sheet of media is fed into the paper path at the sametime. When thick media or media with a slick surface finish is loadedinto the input tray, the frequency of mispick events may increase. Amispick event is when the pick system is unable to pick the top sheet ofmedia from the stack of media. In some cases a skewed-pick event mayoccur. A skew-pick event is where the page is picked and separated fromthe rest of the stack, but some problem causes the page to not beparallel with the paper path direction.

Modern printers are typically designed to print a large number of pagesover the life of the printer. Some parts of the printer may wear outquicker than other parts. For example the pick roller in a pick systemmay wear out before the rest of the print engine. When the pick rollerbegins to wear out, the frequency of mispicks or multi-picks mayincrease. Many printers have pick rollers that are user replaceable.Pick rollers are fairly inexpensive compared to the print engine.Therefore replacing the inexpensive pick roller extends the useful lifeof the more expensive print engine. Currently the pick rollerreplacement part is the same design as the original pick roller.Therefore when the pick roller is replaced, the pick system is stilloptimized for plain paper.

In one example, a number of different pick rollers will be availablewhere each pick roller set is designed or tuned for a different type ofmedia. Because the pick roller is user replaceable, a user can select apick roller set to match the type of media they wish to use. Once thepick roller tuned for that media type is installed, the pick system willhave fewer mispicks or multi-picks for media that is different fromplain paper. When the user is done using the specialty media and isready to go back to plain paper, the original pick roller (or a pickroller tuned for plain paper) can be re-installed back into the printer.

By providing a number of different pick roller sets, with each pickroller set tuned for a different media type or groups of media types,good performance of the pick system can be broadened across a much widerrange of media types (e.g. the gamut of media types the printer willsuccessfully pick is broadened). In some examples, other pieces of thepick system may also be tuned for different media types, for example theseparation roller or separation pad, as well as the spring tensioningdevice. A number of sets of pick parts may be provided with each set ofparts tuned for a different type of media.

FIG. 1 is a schematic of an example pick system 100 for a printer. Picksystem 100 comprises an input tray 102, a pick roller 108, a separationroller 110 and drive rollers 111 and 112. Input tray 102 has a spring106 loaded bottom surface 104. A stack of media 116 is shown loaded intoinput tray 102. Spring loaded bottom surface 104 moves the stack ofmedia 116 upwards as the sheets are fed into the paper path. Pick roller108 contacts the top sheet of media 118 in the input tray 102. As thepick roller rotates (as shown by the arrow) the top sheet of media isseparated from the other sheets in the stack. Sheet 118 is shown movingtowards the nip between drive rollers 111 and drive roller 112.Separation roller 110 prevents more than one sheet of media fromentering the paper path at a time. Sheet 120 is shown inside paper path.Paper path may comprise additional drive rollers, the print zone and theoutput tray, but these items are not shown for clarity.

Pick roller 108 has a tensioning system (114 and 106) that controls theforce between the pick roller and the top sheet of media 118 in theinput tray. The tensioning system may comprise springs, pivot arms,mounting brackets and the like. The amount of force used in tensioningsystem (114 and 106) may depend on the type of media the pick system istuned for. Separation roller 110 prevents multiple sheets of media frombeing passed through the paper path at the same time.

In this example the pick roller 108, the separation roller 110 and atleast one spring in the tensioning system (114 and 106) are userreplaceable. When the printer is shipped, the pick roller 108, theseparation roller 110 and the tensioning system (114 and 106) installedin the printer are tuned for the most commonly used papers (for exampleplain paper) or media types. When the user wishes to use media thatdiffers from the most commonly used plain paper or plain media types,one or more of the user replaceable parts can be swapped out for partstuned for that media. In some examples. the pick roller 108, theseparation roller 110 and a spring in the tensioning system (114 and106) may need to be swapped out to tune the pick system for a particulartype of media. In other examples only the pick roller may need to beswapped out for a different type of media.

In one example the replacement parts come in different sets ofreplacement parts, with each set of replacement parts tuned for adifferent type of media or group of media types. In some examples one ormore of the parts in a set of replaceable parts may be color coded. Thecolor code can be matched up with the type of media that set ofreplacement parts are tuned for. For example, a green color may indicatea set of parts tuned for thin media. A blue color may indicate that theset of replacement parts is tuned for thick or stiff media. In oneexample the set of parts tuned for plain paper are not marked with acolor. In other examples, the set of parts tuned for plain paper will bemarked with a color. There may be a number of different sets ofreplaceable parts. In some examples there may be between 2 and 15different sets of replacement parts, for example 5 sets of replacementparts. The side of a part or the surface of the part may be the areamarked with the different colors or perhaps the whole part structure maybe molded in a particular color.

Some types of media may require three or more user replaceable parts tobe included in the set of replacement parts for that type of media.Other types of media may only require one or two of the user replaceableparts to tune the pick system for that type of media.

When tuning the pick system for different media types, the parameters ofthe different replaceable parts may be varied. FIG. 2 is a sectionalside view of an example pick roller 108. Pick roller 108 comprises hubor axel 228, compression material 226 and outer material 224. Hub 228 isconnected to a drive system that rotates pick roller 108. Compressionmaterial 226 is formed around hub 228. Outer material 224 is attached tothe outer diameter of compression material 226.

Compression material 226 is typically a flexible material, for examplerubber or foam. Compression material in conjunction with the tensioningsystem, controls how much the surface of outer material deforms whenmaking contact with the media. When compression material 226 is softeror more flexible, more of the surface area of outer material contactsthe top sheet of media. Softer or more flexible material can be used totune the pick roller for stiffer or heavy weight media. When compressionmaterial 226 is stiffer or less flexible, less of the surface area ofouter material contacts the top sheet of media. Stiffer or less flexiblematerial can be used to tune the pick roller for thin or light weightmedia. The change in stiffness can be accomplished by a change inmaterial, a change in the physical layout of the part, or both.

Outer material 224 may be selected for its surface properties. Some ofthe surface properties that can be varied include the roughness of thesurface or surface finish, the tackiness or stickiness or the surface,the hardness of the surface, the compliance of the material and thelike. These properties generally control the coefficient of friction ofthe surface of the pick roller. The surface finish can be varied from asmooth finish, to a rough finish, or even a surface with treads orsipings (like a tire). The change in the coefficient of friction of thesurface of the pick roller can be accomplished by a change in material,a change in the surface finish, or both. A smooth finish can be used forthin or light weight media. A rough surface or compliant material can beused for a stiff or heavy weight media. In some examples the pick rollermay be fabricated from a single material and no outer material 224 isused.

Other properties of the pick roller may be varied, for example the widthof the pick roller. A full width pick roller may be used for standardsized paper. A narrower pick roller may be used for media that is not aswide as letter sized paper, for example an envelope.

Similar variations in properties can be used to tune the separationroller or the separation pad for different media types. The tensioningsystem (114 and 106) can be tuned for different media types by changingone or more springs in the tensioning system (114 and 106). A strongerspring force may be used for stiff or heavy weight media and a weakerspring force may be used for thin or light weight media. The materialand design of the roller surface may also be varied to withstand certainpaper additives such as calcium carbonate and the like.

In some examples, a label or mark may be attached to the media packagingmaterial. The label or mark may indicate which set of replaceable partswork best for that type of media. In one example the label may match thecolor code of one of the sets of replaceable parts. In another examplethe label may indicate the set of replaceable parts to use for themedia, for example use the thin media replacement parts. In yet anotherexample, both types of information may be included on the label. In thisway the user can easily select the correct set of replaceable parts forthe media they wish to use.

In some examples the printer may determine that a different type ofmedia is being used. Some printers have sensors that can measuredifferent media properties, for example surface finish, stiffness,color, thickness, and the like. When the sensors detect a different typeof media being used, the printer may recommend a different set of pickparts. In this case the printer may recommend, based on the measuredmedia properties, the set of replaceable pick parts to use with the typeof media loaded in the printer.

In other examples, the printer may determine that a different type ofmedia is in use or that a different set of replaceable pick parts isneeded by tracking errors in the pick system. The printer may trackerrors related to the print path and recommend a set of replaceableparts based on recorded errors or machine analysis of combinations,patterns, or frequency of errors. For example when the printer detects ahigher frequency of mispicks, the printer may recommend a set ofreplacement parts tuned for stiffer or heavy weight media. When theprinter detects a higher frequency of multi-picks, the printer mayrecommend a set of replacement parts tuned for thinner or light weightmedia. The recommendation may be triggered when the frequency of errorsexceeds a threshold.

FIG. 3 is an example block diagram of a printer. Printer comprises aprocessor 302, memory 304, input/output (I/O) module 306, print engine308, display 314 and controller 310 all coupled together on bus 312. Insome examples printer may also have a user interface module, an inputdevice, and the like, but these items are not shown for clarity.Processor 302 may comprise a central processing unit (CPU), amicro-processor, an application specific integrated circuit (ASIC), or acombination of these devices. Memory 304 may comprise volatile memory,non-volatile memory, and a storage device. Memory 304 is anon-transitory computer readable medium. Examples of non-volatile memoryinclude, but are not limited to, electrically erasable programmable readonly memory (EEPROM) and read only memory (ROM). Examples of volatilememory include, but are not limited to, static random access memory(SRAM), and dynamic random access memory (DRAM). Examples of storagedevices include, but are not limited to, hard disk drives, compact discdrives, digital versatile disc drives, optical drives, and flash memorydevices.

I/O module 306 is used to couple printer to other devices, for examplethe Internet or a computer. Printer has code, typically called firmware,stored in the memory 304. The firmware is stored as computer readableinstructions in the non-transitory computer readable medium (i.e. thememory 304). Processor 302 generally retrieves and executes theinstructions stored in the non-transitory computer-readable medium tooperate the printer and to execute functions. In one example, processorexecutes code that recommends a replacement part set.

FIG. 4 is an example block diagram of the processor 302 coupled tomemory 304. Memory 304 contains software 420. Software 420 contains apick system module 424. The processor 302 executes the code in picksystem module 424 to track pick system errors and recommend replacementparts sets based on the tracked errors. The recommend replacement partset can be displayed on the display 314 (see FIG. 3).

What is claimed is:
 1. A part system for a printer, comprising: at leasttwo sets of replacement parts for a pick system in the printer; a firstof the at least two sets of replacement parts is tuned for media of afirst type; a second of the at least two sets of replacement parts istuned for media of a second type different than the first type of media.2. The part system of claim 1, wherein each set of replacement parts hasat least one part selected from the following group of part types: apick roller, a separation pad, a separation roller and a spring.
 3. Thepart system of claim 1, wherein at least one part in each set ofreplacement parts is color coded for the type of media the set ofreplacement parts is tuned for.
 4. The part system of claim 1, whereeach part in the set of replacement parts is user replaceable.
 5. Thepart system of claim 1, further comprising: a first pick roller tunedfor media of the first type; a second pick roller tuned for media of thesecond type; wherein at least one pick roller feature of the first pickroller is different than the at least one pick roller feature of thesecond pick roller where the at least one pick roller feature isselected from the following group of pick roller features: coefficientof friction of the surface of the pick roller, compressibility of thepick roller, width of the pick roller and material of the pick roller.6. The part system of claim 1, further comprising: a printer, theprinter comprising: a controller coupled to a display and a pick system,the pick system having at least one user replaceable part that can beswapped with a part in each of the at least two sets of replacementparts: the controller to display a recommended set of replacement partswhen media of a different type is detected in the pick system.
 7. Thepart system of claim 6, wherein the controller detects media of adifferent type by tracking errors, error patterns, or error frequenciesin the pick system.
 8. The part system of claim 6, further comprising: asensor to detect media properties of media in the pick system whereinthe controller detects media of a different type by a change in thedetected media properties.
 9. The part system of claim 1, furthercomprising: packaging material for media, the packaging material havinga label, the label indicating one of the at least two sets ofreplacement parts that work with media packaged in the packagingmaterial.
 10. The part system of claim 1, where there are between 2 and15 different sets of replacement parts and each set of replacementsparts is tuned for a different media type.
 11. A method of printing,comprising: selecting a type of media; loading one of at least two setsof replaceable parts into a pick system of a printer where the one of atleast two sets of replaceable parts is selected to match the selectedmedia type: loading the media into the printer and printing on themedia.
 12. The method of printing of claim 11, wherein each set ofreplaceable parts has at least one part selected from the followinggroup of part types: a pick roller, a separation pad, a separationroller and a lift spring.
 13. The method of printing of claim 11,wherein a label on packaging material for the media indicates the set ofreplaceable parts to be selected to match the selected media type. 14.The method of printing of claim 11, wherein a first one of the at leasttwo sets of replaceable parts has a first pick roller tuned for media ofa first type; a second one of the at least two sets of replaceable partshas a second pick roller tuned for media of a second type; wherein atleast one pick roller feature of the first pick roller is different thanthe at least one pick roller feature of the second pick roller where theat least one pick roller feature is selected from the following group ofpick roller features: coefficient of friction of the surface of the pickroller, compressibility of the pick roller, width of the pick roller andsurface material of the pick roller.
 15. A non-transitory computerreadable storage medium having computer executable instructions storedthereon, that when executed by a processor, perform the following steps:determine when the type of media loaded into a pick system of a printerhas changed; recommend one set of replacement parts from a plurality ofsets of replacement parts to be used with the media in the pick system.16. The non-transitory computer readable storage medium of claim 15,wherein determining when the type of media loaded into a pick system ofa printer has changed is determined by tracking errors in the picksystem.